The present invention relates to a mounting assembly for affixing antenna platforms and antenna mounting arms to poles, and more particularly, to a mounting assembly that is adaptable to provide a tight fit on poles over a wide range of diameters.
Antenna poles or towers have long been in use for the transmission, reception and forwarding of radio and television signals. In addition, microwave antennas have come into frequent demand and usage for cellular communications. Such poles generally range in height from 80 to 220 feet and more. Based on the variety of heights and load carrying capacities of these poles, pole diameters may vary greatly. Typically, these types of antenna poles range from approximately 1 to 5 foot in diameter. Furthermore, the poles may have a uniform diameter or be tapered from a thicker diameter at the bottom to a thinner one at the top.
In order to mount antenna platforms or antenna mounting arms on poles, a variety of clamps have been developed. One such clamp is illustrated in U.S. Pat. No. 6,018,325 to Lundgren, herein incorporated by reference. The clamp in Lundgren is of a common clam shell variety having two substantially semi-circular clamp members which are placed about the pole and bolted together. Lundgren also discloses a clamp having a faceted clamping surface for matching up against a faceted pole. A drawback with the clamps disclosed in Lundgren is that the clamps must be individually sized to the diameter of the pole thereby greatly increasing manufacturing costs and the number of clamps which must be stocked. As such, it would be desirable to provide a pole clamp having the flexibility to be used over the complete range of pole diameters.
There are some clamping assemblies that provide some adjustability for clamping to poles of different sizes. For example, in U.S. Pat. No. 5,867,132 to Blasing, et al, herein incorporated by reference, an adjustable clamp is disclosed which can accommodate a pole with a diameter of 1.75xe2x80x3 to 4.5xe2x80x3. Although this clamp does provide some adjustability, it is still basically a clam shell design, and could not serve as a basis for a single clamp sized to accommodate the range of antenna pole diameters set forth above.
Another antenna support bracket is disclosed in U.S. Pat. No. 6,043,795 to Strieffler et al, herein incorporated by reference. Although this bracket also provides some capability for use on poles of various diameters, the configuration of the clamp and support lug could not be universally used over the complete range of antenna pole diameters. For instance, if the bent clamp in Strieffeler was made large enough to accommodate very large diameter poles, then the clamp ends would need to be spaced further apart than the largest diameter on which it is to be used. This wide spacing would then make the clamp incapable of providing sufficient clamping force on small diameter poles. Furthermore, if the lug and clamp were made large enough to fit the largest diameter poles, it would provide large, awkward and unsightly protrusions from a smaller diameter pole. As such, it is a object of the present invention to provide a clamping assembly that can be used over the complete range of antenna poles and will not provide excess protrusions when used on smaller diameter poles.
Another form of adjustable pole clamp is disclosed in U.S. Pat. No. 4,755,830 to Plunk, herein incorporated by reference. The problem with this clamp is that the adjustable set screws do not provide sufficient clamping surface to provide a secure fit for large platforms. Also, if the clamping ring was large, the length of the set screws would be excessive on small diameter poles compounding the instability of this clamp. In addition, this design would also provide excessive protrusion when used on smaller poles if the clamping ring were made large enough for larger diameter poles.
In summary, it is an object of the present invention to overcome the shortcomings of the prior art by providing a clamping assembly which would be useable over a wide range of diameter poles and provide a secure mount without creating excessive protrusions when used on smaller diameter poles.
It is a feature of the invention to provide a mounting assembly for affixing an antenna platform or mounting arm to a pole. The mounting assembly includes a plurality of clamps for postioning about the circumference of the pole, and each of the clamps has a pole mounting surface contoured to mount securely to a variety of pole circumferences. Three clamps are utilized in the preferred embodiment. The mounting assembly also includes a plurality of interconnection members extending between the mounting clamps for securing the mounting clamps to the pole.
Another feature of the invention is that each of the clamps includes a pair of axially offset side plates.
It is also a feature of the invention that the side plates in each pair are parallel to one another.
A further feature of the invention is that the side plates are identical.
Also, a feature of the invention is that the side plates include connecting extensions for attachment of the interconnection members.
Another feature of the invention is that the mounting assembly includes reinforcing plates attached to the connecting extensions and that the reinforcing plates having apertures for receiving the interconnection members.
The mounting assembly also includes a middle support plate attached to and interconnecting each pair of side plates. The middle support plate is configured for receipt and attachment of the platform to be supported.
An additional feature of the invention is that the mounting assembly has a flange attached to and extending between each pair of side plates. The flange is also attached to the middle support plate for providing structural stability to the clamps.
Another feature of the invention is that the mounting assembly may include a shim plate adjustably connected to at least one of the clamps for tightening the fit of the clamps to the pole.
A further aspect of the invention is that the interconnection members include rods having threaded ends and nuts threadable onto the threaded ends for adjustably tightening the clamps about the pole.
Another feature of the mounting assembly is that the size of the clamps remains constant as the pole diameter is varied, but the length of the interconnection members is increased as the pole diameter is increased.